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1.
Biomater Sci ; 9(9): 3445-3452, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33949456

RESUMO

Multidrug resistance (MDR) is one of the prime reasons for the failure of cancer chemotherapy, which continues to be a great challenge to be solved. In this work, α-tocopherol succinate (α-TOS) and doxorubicin (DOX)-based self-delivery nanomedicine (designated as α-TD) is prepared to combat drug resistance for cancer synergistic chemotherapy. Carrier-free α-TD possesses a fairly high drug loading rate and improves the cellular uptake via the endocytosis pathway. More importantly, the apoptotic inducer α-TOS could elevate the reactive oxygen species (ROS) generation, disrupt mitochondrial function and reduce adenosine 5'-triphosphate (ATP) production, which facilitate the intracellular drug retention while decreasing its efflux. As a result, α-TD achieves a considerable synergistic chemotherapeutic effect against drug resistant cancer cells. Moreover, it also exhibits a preferable inhibitory effect on tumor growth with a low system toxicity in vivo. This synergistic drug self-delivery strategy would open a new window for developing carrier-free nanomedicine for overcoming drug resistance in cancer therapy.


Assuntos
Antineoplásicos , Nanopartículas , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Portadores de Fármacos/farmacologia , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Humanos , Células MCF-7 , Nanomedicina
2.
ACS Nano ; 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33236625

RESUMO

Self-delivery of photosensitizer and immune modulator to tumor site is highly recommendable to improve the photodynamic immunotherapy yet remains challenging. Herein, self-delivery photoimmune stimulators (designated as iPSs) are developed for photodynamic sensitized tumor immunotherapy. Carrier-free iPSs are constructed by optimizing the noncovalent interactions between the pure drugs of chlorine e6 (Ce6) and NLG919, which avoid the excipients-raised toxicity and immunogenicity. Intravenously administrated iPSs prefer to passively accumulate on tumor tissues for a robust photodynamic therapy (PDT) with the induction of immunogenetic cell death (ICD) cascade to activate cytotoxic T lymphocytes (CTLs) and initiate antitumor immune response. Meanwhile, the concomitant delivery of NLG919 inhibits the activation of indoleamine 2,3-dioxygenase 1 (IDO-1) to reverse the immunosuppressive tumor microenvironment. Ultimately, the photodynamic sensitized immunotherapy with iPSs efficiently inhibit the primary and distant tumor growth with a low system toxicity, which would shed light on the development of self-delivery nanomedicine for clinical transformation in tumor precision therapy.

3.
Implant Dent ; 21(4): 340-3, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22814561

RESUMO

PURPOSE: To analyze the biomechanics of 3 designs of implant treatment for 3 teeth missing in posterior low arch quadrants. MATERIAL AND METHODS: A posterior portion of the human mandible missing 44, 45, 46 and three 4.1 × 10 mm threaded ITI implants with crowns were used to construct the finite element model. According to 3 implants being single, splinted or 2 implants support fixed partial denture (FPD) fixed in bone segments. Three implant support conditions were prepared with ANSYS 10.0. A load of 100 N was applied at the central fossa of the occlusal surfaces of the crowns at 45 degrees buccolingually along the triangular ridge of the buccal cusp. The von Mises stress and strain distributions in periimplant bone were observed. RESULTS: The results demonstrated that the von Mises stress in the supporting bone of the 2-implant supported FPD significantly increased compared with that in the 3-implant replacement. Meanwhile, when 3 implants were splinted, only the median implant had a decreased and more homogenous stress distribution, and the other implants did not exhibit significant differences when splinted. CONCLUSION: This study suggests that when space and cost permit, a 2-implant supported FPD should not be used, and 1 implant for each missing tooth being single is recommended.


Assuntos
Implantes Dentários , Análise de Elementos Finitos , Imageamento Tridimensional/métodos , Arcada Parcialmente Edêntula/cirurgia , Mandíbula/cirurgia , Planejamento de Assistência ao Paciente , Silicatos de Alumínio/química , Fenômenos Biomecânicos , Força de Mordida , Simulação por Computador , Coroas , Materiais Dentários/química , Porcelana Dentária/química , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Análise do Estresse Dentário/instrumentação , Planejamento de Dentadura , Prótese Parcial Fixa , Humanos , Arcada Parcialmente Edêntula/reabilitação , Modelos Biológicos , Compostos de Potássio/química , Estresse Mecânico , Titânio/química
4.
Int J Oral Sci ; 4(4): 218-20, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23306858

RESUMO

To investigate whether masticatory fatigue affects the fracture resistance and pattern of lower premolars restored with quartz-fiber post-core and full crown, 44 single rooted lower premolars recently extracted from orthodontic patients were divided into two groups of 22 each. The crowns of all teeth were removed and endodontically treated and then restored with quartz-fiber post-core and full crown. Twenty-two teeth in one group were selected randomly and circularly loaded at 45° to the long axis of the teeth of 127.4 N at a 6 Hz frequency, and the other group was not delivered to cyclic loading and considered as control. Subsequently, all teeth in two groups were continually loaded to fail at 45° to the long axis of the teeth at a crosshead speed of 1 mm⋅min(-1). The mean destructive force values were (733.88±254.99) and (869.14±280.26) N for the experimental and the control group, respectively, and no statistically significant differences were found between two groups (P>0.05). Bevel fracture and horizontal fracture in the neck of root were the major fracture mode of the specimens. Under the circumstances of this study, it seems that cyclic loading does not affect the fracture strength and pattern of the quartz-fiber post-core-crown complex.


Assuntos
Força de Mordida , Ligas de Cromo/química , Coroas , Técnica para Retentor Intrarradicular/instrumentação , Quartzo/química , Dente não Vital/reabilitação , Condicionamento Ácido do Dente/métodos , Adulto , Dente Pré-Molar , Planejamento de Prótese Dentária , Falha de Restauração Dentária , Análise do Estresse Dentário/instrumentação , Humanos , Teste de Materiais , Metacrilatos/química , Ácidos Fosfóricos/química , Cimentos de Resina/química , Estresse Mecânico , Fraturas dos Dentes/fisiopatologia , Raiz Dentária/lesões
5.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 46(4): 233-6, 2011 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-21612714

RESUMO

OBJECTIVE: To assess and compare the peri-implant stress distribution of three posterior implants under immediate loading with 4 different bone qualities using three dimensional (3D) finite element (FE) analysis. METHODS: A 3D finite element model representing three implants in a portion of mandible at the 654 region was developed, and three implants received a crown each. Four types of bone qualities (B1, B2, B3 and B4) were designed for the model. Load of 100 N was applied on the occlusal surfaces of the crowns at a 45° angle to the vertical axis of the implants. RESULTS: Von Mises stresses in the peri-implant bone of 4 in bone quality from B1 to B4 were (13.17 ± 9.32), (12.95 ± 9.14), (15.00 ± 9.44), and (16.81 ± 10.74) MPa, and those of 5 were (15.51 ± 10.32), (14.73 ± 8.96), (16.79 ± 8.40), and (18.34 ± 8.45) MPa. Stress in bone quality B4 showed the highest value, followed by B3 bone, the lowest stress were found in B1 and B2 bone. It was significantly different (P < 0.05). However, von Mises stresses in different quality of bone around 6 [(42.45 ± 25.71), (41.66 ± 25.29), (42.70 ± 23.24), (42.06 ± 23.66) MPa] were close to each other, and were as twice or three times as those of 4 and 5, irrespective of different bone qualities. CONCLUSIONS: The stress distribution around implant under immediate loading was not only affected by different bone qualities, but also by the direction of loading, and the latter may have a greater impact when a severe load delivered.


Assuntos
Densidade Óssea/fisiologia , Cemento Dentário/fisiologia , Implantes Dentários para Um Único Dente , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Humanos , Imageamento Tridimensional , Mandíbula/fisiologia , Estresse Mecânico
6.
J Oral Maxillofac Surg ; 69(6): 1718-25, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21277061

RESUMO

PURPOSE: To develop a feasible intraoperative guiding device using computer-aided design and computer-aided manufacturing of individual templates to permit anatomic fracture reduction of zygomatic-orbitomaxillary complex (ZOMC) comminuted fractures. The simplicity and accessibility of this method should allow its widespread clinical application. MATERIALS AND METHODS: Under an institutional review board-approved protocol, diverse ZOMC fracture types were created in 6 cadaver heads with a hammer and a saw, and preoperative multislice spiral computerized tomography scan and 3-dimensional reconstruction were performed. Three individual templates were made by computer-aided design and computer-aided manufacturing, and the fractures were repaired under the guidance of individual templates. A clinical case was carried out with this method. After surgery, the outcome evaluation was completed by superimposing the postoperative computed tomographic model onto the planned model. RESULTS: Successful planning and repositioning of the 6 cadavers and a clinical patient were achieved using this method. Computer-aided design and computer-aided manufacturing of individual templates were successfully used in all cases at the time of surgery. Postoperative computed tomographic scans confirmed anatomic repair in all cases. CONCLUSIONS: A feasible intraoperative ZOMC fracture monitoring and reduction guidance device has been developed. This technique is a simple, economical, and readily accessible method of comminuted ZOMC fracture reduction that can be learned and used rapidly.


Assuntos
Fraturas Cominutivas/cirurgia , Fraturas Maxilares/cirurgia , Fraturas Orbitárias/cirurgia , Cirurgia Assistida por Computador , Fraturas Zigomáticas/cirurgia , Adulto , Cadáver , Desenho Assistido por Computador , Fraturas Cominutivas/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Técnicas In Vitro , Masculino , Fraturas Maxilares/complicações , Fraturas Maxilares/diagnóstico por imagem , Fraturas Orbitárias/complicações , Fraturas Orbitárias/diagnóstico por imagem , Tomografia Computadorizada Espiral , Fraturas Zigomáticas/complicações , Fraturas Zigomáticas/diagnóstico por imagem
7.
Ann Plast Surg ; 66(1): 88-91, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20842002

RESUMO

Various modifications have been described to improve the accuracy in intraoral vertical ramus osteotomy (IVRO), but there was not a measurable facility to determine the osteotomy line. The purpose of this study was to evaluate the accuracy of the computer tomography (CT)-based osteotomy template on cadaver mandibles and to assess the outcome after IVRO correcting mandibular prognathism. Four human wet cadaver heads were subjected to a high-resolution multislice spiral CT scan. After the virtual osteotomies in the planning program, the individual osteotomy templates were produced by stereolithography. A stable and secure fit of the stereolithographic templates was achieved via the individual CT-based osteotomy template. The osteotomy lines were performed exactly as planned in the virtual osteotomies planning program. Similar sound outcome was also observed in the clinic. Use of the CT-based osteotomy templates is a safe method for osteotomy. It is rather convenient for vertical osteotomy in IVRO increasing the intraoperative accuracy and efficiency.


Assuntos
Simulação por Computador , Desenho Assistido por Computador , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Mandíbula/cirurgia , Osteotomia/métodos , Prognatismo/cirurgia , Tomografia Computadorizada Espiral/métodos , Interface Usuário-Computador , Humanos , Modelos Anatômicos , Prognatismo/diagnóstico por imagem , Adulto Jovem
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